Pass-in the initial value when performing a POST on Workflow Action. This fixes the call to self.changed_data, it allows django forms to be able to compare initial value with current value.

Fixes bug 1153697.

Change-Id: I21846487ada34f3b007a545bcdcba400bd044af5
Merge "Pass-in the initial value when performing a POST on Workflow Action. This fixes the call to self.changed_data, it allows django forms to be able to compare initial value with current value."